This submission for a Mentored Patient-Oriented Award is designed to enhance clinical training and research expertise in the area of major depressive disorder (MDD) in Parkinson's patients. Research Plan: The purpose of this study is to assess the efficacy of cognitive behavior therapy (CBT) for depression in Parkinson's disease. The present study will randomize untreated depressed individuals with Parkinson's disease to either CBT or to a wait-list control group. Both groups will receive CBT (either immediately or delayed in the wait-list control), which will provide them with concrete strategies and skills for coping with depression, Parkinson's disease, and associated functional impairment, and may provide optimal benefit for patients with Parkinson's disease and MDD. We hypothesize that there will be a greater change in depressive severity scores from baseline to endpoint (12th week) in the group receiving CBT compared to the wait-list control group. Relevance to Public Health: Assessing the benefits of CBT in this population may be extremely useful, as there have never been randomized studies using this effective treatment modality among Parkinson's patients. This study provides the opportunity to develop specific cognitive behavioral techniques for depressed patients with a primary diagnosis of Parkinson's disease, and to determine which interventions may be helpful at different stages of disease progression. Environment: The proposed study will be a collaboration between the Depression Program and the Movement Disorders Clinics at the Massachusetts General, the Beth Israel Deaconess, and the Brigham &Women's Hospitals. Career Development Plan: Training will include the following: receiving mentorship and consultation with experts in the areas of Parkinson's disease and depression, completing formal coursework, training in the assessment of treatment of both depression and Parkinson's disease, attending scientific meetings, and having mentored data analysis and manuscript preparation. The three specific career goals relate to developing expertise in: 1) depression and Parkinson's disease research;2) the implementation of CBT and its applicability to movement disordered patients;and 3) academic and research activities needed to achieve the goal of becoming an independent researcher.